StringUtils.java Source code

Introduction

Here is the source code for StringUtils.java

Source

/*
JSPWiki - a JSP-based WikiWiki clone.
    
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements.  See the NOTICE file
distributed with this work for additional information
regarding copyright ownership.  The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License.  You may obtain a copy of the License at
    
   http://www.apache.org/licenses/LICENSE-2.0
    
Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied.  See the License for the
specific language governing permissions and limitations
under the License.    
 */

import java.security.SecureRandom;
import java.util.Properties;
import java.util.Random;

public class StringUtils {

    /**
     *  Gets an integer-valued property from a standard Properties
     *  list.  If the value does not exist, or is a non-integer, returns defVal.
     *
     *  @since 2.1.48.
     *  @param props The property set to look through
     *  @param key   The key to look for
     *  @param defVal If the property is not found or is a non-integer, returns this value.
     *  @return The property value as an integer (or defVal).
     */
    public static int getIntegerProperty(Properties props, String key, int defVal) {
        String val = props.getProperty(key);

        return parseIntParameter(val, defVal);
    }

    /**
     *  Gets a boolean property from a standard Properties list.
     *  Returns the default value, in case the key has not been set.
     *  <P>
     *  The possible values for the property are "true"/"false", "yes"/"no", or
     *  "on"/"off".  Any value not recognized is always defined as "false".
     *
     *  @param props   A list of properties to search.
     *  @param key     The property key.
     *  @param defval  The default value to return.
     *
     *  @return True, if the property "key" was set to "true", "on", or "yes".
     *
     *  @since 2.0.11
     */
    public static boolean getBooleanProperty(Properties props, String key, boolean defval) {
        String val = props.getProperty(key);

        if (val == null)
            return defval;

        return isPositive(val);
    }

    /**
     *  Fetches a String property from the set of Properties.  This differs from
     *  Properties.getProperty() in a couple of key respects: First, property value
     *  is trim()med (so no extra whitespace back and front), and well, that's it.
     *
     *  @param props The Properties to search through
     *  @param key   The property key
     *  @param defval A default value to return, if the property does not exist.
     *  @return The property value.
     *  @since 2.1.151
     */
    public static String getStringProperty(Properties props, String key, String defval) {
        String val = props.getProperty(key);

        if (val == null)
            return defval;

        return val.trim();
    }

    /**
     *  Returns true, if the string "val" denotes a positive string.  Allowed
     *  values are "yes", "on", and "true".  Comparison is case-insignificant.
     *  Null values are safe.
     *
     *  @param val Value to check.
     *  @return True, if val is "true", "on", or "yes"; otherwise false.
     *
     *  @since 2.0.26
     */
    public static boolean isPositive(String val) {
        if (val == null)
            return false;

        val = val.trim();

        return val.equalsIgnoreCase("true") || val.equalsIgnoreCase("on") || val.equalsIgnoreCase("yes");
    }

    /**
     *  Parses an integer parameter, returning a default value
     *  if the value is null or a non-number.
     *  
     *  @param value The value to parse
     *  @param defvalue A default value in case the value is not a number
     *  @return The parsed value (or defvalue).
     */

    public static int parseIntParameter(String value, int defvalue) {
        int val = defvalue;

        try {
            val = Integer.parseInt(value.trim());
        } catch (Exception e) {
        }

        return val;
    }

}